Development of antioxidant active packaging films with slow release properties incorporated with tea...

Slow release active packaging films can realize the sustained release of active agents and prolong the shelf life of food. For this aim, a novel slow release active polyvinyl alcohol (PVA) film was developed by using solution casting method. With porous starch loaded with tea polyphenols (PSTP) as core material and maltodextrin (MD) as wall material, PSTP@MD microcapsules were prepared using freeze drying method and used as slow release carrier of tea polyphenols (TP) in the active films. The interactions between PSTP@MD microcapsules and PVA molecular chains were physical interactions. In addition, the relative crystallinity of the slow release active films was reduced to 23.74 %. The addition of PSTP@MD microcapsules can enhance the ductility of active films and reduce the water content and swelling degree of active films by 46.74 % and 54.38 %, respectively. Moreover, the thermal stability, water vapor and ultraviolet barrier properties of active films were promoted. The transparency and antioxidant activity of active films was high, and the radical scavenging activity of active films was 58 %. The encapsulation of TP with PSTP@MD microcapsules can realize the slow release of TP. The slow release active films had antioxidant activity and sustained release properties, which could be used as an active packaging film to extend the shelf life of food.